Map data or geographic data is used in computer-based systems that provide useful features to users. For example, the computer-based systems may provide the identification of routes to destinations or points of interests. A navigation system may determine the optimum route to be taken by the end user to travel from an origin to a destination location from map data stored in a map database. Similarly, the navigation system may query the map data for nearby points of interest or provide other map-related functions.
As new roads are built, other roads are closed, or locations of business are changed, the geographic data becomes out of date. These changes to the physical infrastructure must be detected in order to update the map database. One of the usual changes in the infrastructure of the physical road network represented in the map database is the change of a conventional intersection to a roundabout. This change is particularly hard to detect because two roadways that simply intersected in straight lines now merge into a common path for a short amount of time on a relatively small area extend. Challenges remain in the automation of the detection of roundabouts from probe data.